People infected in the West African Ebola outbreak can be offered untested drugs, the World Health Organisation said on Tuesday, but the scarcity of supplies has raised questions about who gets priority access to treatment.

Liberia said it planned to treat two infected doctors with an unproven Ebola medicine called ZMapp. They would become the first Africans to receive the drug, which has been given to a Spanish priest who later died and two U.S. aid workers.

The outbreak is the world's largest and deadliest and the U.N. agency last week declared it an international health emergency. The WHO has appealed for funds and medical staff to supplement health care in one of the poorest regions in the world.

So far, 1,013 people have died, the vast majority in Guinea, Liberia and Sierra Leone. Two have died in Nigeria.

The suffering has been exacerbated by health services that are struggling to cope.

On Tuesday, Liberian Ceceilia Gbelley lay on the grass among a group of seven outside an Ebola treatment centre at Monrovia's Elwa hospital because there was no space for them inside. All said they feared they might have the disease.

"I'm very weak. My chest is burning," said Gbelley, who had nursed her aunt while she vomited blood and showed other symptoms of the virus. The aunt died and Gbelley then fell ill. She said she rode to the hospital in a shared taxi.

In a sign of the desperation for even experimental medicine as the death toll mounts, Twitter users in West Africa, where Ebola is killing around 60 percent of patients who become infected, created the #GiveUsTheSerum hashtag.

There are no licensed treatments or vaccines for Ebola, a contagious haemorrhagic disease, but several biotech companies and research teams have been working on potential drugs.

The WHO's panel of medical ethicists said several experimental drugs had passed the laboratory and animal study phases of development and should be fast-tracked into clinical trials and made available for compassionate use.

"There was unanimous agreement among the experts that in the special circumstances of this Ebola outbreak it is ethical to offer unregistered interventions as potential treatments or prevention," the WHO's assistant director general Marie-Paule Kieny said after an ethics panel published its guidance.

The WHO meeting was called after ZMapp, made by U.S. biotech company Mapp Biopharmaceutical, was given to the two U.S. aid workers infected in Liberia. Kieny said she had heard reports that the treatment had a swift